Apparatus for printing cinematographic films.



P. D. BREWSTER.

APPARATUS FOR PRINTINGGINEMATOGRAPHIC FILMS.

APPLICATION FILED MAYI, 1915.

V UUUUUUUUDUUEIUU Patented July 10, 1917.

3 SHEETS-SHEET 1.

DUUUUUUUUUUUUUUU P. D. BREWSTER.

APPARATUS FOR PRINTING CI'NEMATOGRAPHIC FILMS. APPLICATION FILED MAY l. 1915.

1 ,233, 1 76. Patented July 10, 1917.

3 SHEETS-SHEET 2.

WITNESSES:

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A TTOH/VEV 5 P. D. BREWSTER.

APPARATUS FOR PRINTING CINEMATOGRAPHIC FILMS. APPLICATION FILED MAY1,I915.

1,233, 1 76. Patented July 10, 1917.

3 SHEETS-SHEET 3.

WITNESSES; v INVENTOR v (p F. 4). 11mm}; a W 1 A BY v A #1,, f e. 914; L

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- PERCY DOUGLAS BREWSTER, OF EAST ORANGE, NEW JERSEY.

APEPARATUS FOR PRINTING CINEMATOGRAPHIC FILMS.

Application filed May 1, 1915. Serial No. 25,113.

To all whom it may concern: 1

Be it known that I, PERCY D. BREWSTER, a citizen of the United States, residing at East Orange, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Apparatus for Printing cinematographic Films, of which tudinally whereas the alternate arrange the following is a full, clear, and exact description.

The invention which forms the subject of the present application relates to printing on the two sides of a cinematographic film from a negative having two series of images taken through differently colored filters, as forexample one series throu h a red and the other through a green fi lter. The two series of ne ative images are preferably on the same side of 'the negative film but with the images of one series in alternation with those of the other; that is, designating the images by the color of the filtore through which they were produced, each red imagev is followed by a green image, and vice versa. The invention is not, however, limited to the alternate arrangement, for the two series of images may be side by side, but the latter arrangement requires as will be readily understood from the subjoined description by persons skilled in the art) that the negative, or the positive, film be shiftedlat'erally aS well as longiment requires only longitudinal movement of the films, with correspondingly simpler printing apparatus and less liability of errors in securing suitable registration of the red and green positive images, which; it will be understood, are not in alternation but are, so-to speak, superposed one on the other.

The method of exposing the negative film in the taking camara is to a certain extent immaterial. For example, red and green exposures can be made in alternation, as in the so-called kinemacolor process, or they can be made slmultaneously as by 'splitting'the light from the lens.

Two forms of the invention are illustrated in the accompanying drawings, in which- \-Figure 1 shows a piece of negative film having alternating images, taken through differently colored filters. In this. figure the two filters are assumed to be red and green, as usual, and the corresponding Specification of Letters Patent.

Patented Julyv 10, 1917.

ent base or support 2 with sensitive coatings or emulsions, 3, 4, on its two sides. i Fig. 3 is a plan view, partly in horizontal section, of the preferred form of printing apparatus, or printer. In this apparatus the negative images are projected upon the positive films bv means of a lens, the light from the latter being split and reflected, part to one side and part to the other side of the positive film. l

Fig. 3 is a plan View of the reflecting surface of a fsplitting prism suitable for use in a printer of the type illustrated in Fig. 3. Fig. 3 is a detail section on line 1 of Fig. 1. Fig. 4: is an elevation of one of the two shutters used in Fig. 3.

to one. side and then to the other side of the positive film; using for the purpose a mirror which is swung into and out of the path of the rays from the lens.

Fig. 9 is a sectional plan view of a twolens printer, of the type shown in my copending applications Ser. Nos. 870,754, and 23,025.

Fig. 9" is a detail section on line 9 of Fig.

9, illustrating the adjustable mounting of 1 two of the mirrors therein shown.

Fig. 10 is an elevation of the shutter used in Fig. 9.

The negative, illustrated in Fig. 1 as having images R taken through a red filter and, in alternation therewith, images G taken through a green filter, is fed intermittently through a negative filmgate 5, Fig. 3, and is illuminated in any convenient manner. If the film is of the opaque type, as described in my copending application Ser. No. 13,595, the film is illuminated on the front and the clear spaces 16 between the silver bands, and

light is reflected therefrom to the lens; but I prefer the negative to be transparent, in which case it is illuminatedfrom the rear, as by means of a lampb. The light from the-negative is received by the lens 6. and

projected into the splitting, device 78 adaptedto divide the light into-two part'sg one part refiected'by the silver bands or'bars 17 on the rear surface a..b of prism 7 and thence to a mirror 9 by which it is reflected I to the emulsion 3 on th e positive film 2;

while the other part is transmitted by the throng the other prism, 8, to the mirror 10 by which it is-reflected'to the emulsion 4 on the positive film in the-positive filmgate 11'. It will be readily-understood that with the lens and the transmitting reflecting devices properly positioned the two images thus projected will be complete and will have any desired degree of accuracy of registration on. the positive film. To get the desired degree of accuracy in registration the images can'be shifted horizontally by turning the prism 7'8 on its vertical center-pin and'vertically by. tilting the reflectors 9,10, on-their horizontal axes' For this purpose the refiectors are mounted. on pins or shafts 9,

I -10, Figs. 3 and 3 which are in turn mounted'in the standards 9, 10", while the arms 9, 10, are rovided with ca stan screws 9, -10, wor 'ng between the ase-- plates 9, 10, and the upper plates9, 10.

The negative images being in alternation, as indicated in Fig. 1,'the red and green images cannot, in the printerillustrated, be projected on the positive film simultaneously. Instead, one negative image, say a holes at the edges of the negative and positive films respectively. On the shaft of the I sprocket 20,is a Geneva'star-wheel or Maltese cross 24 (see also Fig. 6) actuated by a pin:

.wheel 22 having two pins, 27, at diametrically opposite points, so that the star-wheel or cross will be actuated twice in each revolution ofthe pin wheel. The positive s rocket shaft is equipped with a similar s ar-wheel or cross 25, driven by a pin-wheel 23 having a single pin 28. Hence the cross- 25 is actuated but once in each revolution of its pin-wheel.

, The two pin-wheels are mounted on the shafts 29, 29 connected by bevel gears 26 so as to rotate in unison at the meagre same speed. Oneof the shafts,as'29, can be extended past the bevel gearing for connection with suitable driving mechanism, not shown.

- The exposure of the positive film is controlled by .rotary shutters 12, 13', of the disk type on opposite sides of, the film gate 11" and carried by the shaft 14 mounted .in a

bearing 15. The shaft is-rotated in any convenient way, as by the shaft 29, Fig. 3 through bevel gearing 14: and shaft 14 Each shutter is composed of tivo disks (2, d, Fig. 4, of about 180 extent, more or less, and-capable of relative rotary adjustment on the shaft 14 to.vary the angular width of the sector-shaped exposure opening and thereby varying the duration -of the exposure. The shutters are arranged with the exposure openings diametrically opposite each other, so that the two sides of the film will be exposed in alternation and they are so arranged that the exposures occur only when the two films are attrest, as will be readily understood.

In conjunction with the shutters 12, 13, I may provide a shutter, as 5*, to intercept the printing light while either film is in motion. This shutter may be like 12 (or 13), and connected to shaft 29, Fig. 5, by a shaft 59 and bevel gearing (not shown), to rotate at-the proper rate.

The operation of the printer will now be readily understood. Both films, being at rest, one of the images on the negative film 1, for exampleone of the R images, is projected upon the emulsion 3 of the positive film. through the sector-shaped exposure openingiin shutter 13, shutter 12 being in the path of the rays from mirror 10 and hence preventing projection of the image upon emulsion 2. The shutters beingin motion, exposure of emulsion 3 is ended, whereupon the negative film is shifted one image-- space, bringing a G image tothe film gate 5, after which the exposure opening in shutter 12 reaches the film gate 11 and exposes emulsion 4:. When this exposure is ended and while both sides of the positive film are protectedby the shutters both films are shifted one image-space, bringing the next It image of the negative to the film gate 5 and an unexposed portioii of the positive to t film gate 11. The cycle thus describe is 'repeated as often as necessary. It will be understood that when the shutter 5 is used, the printing light is cut ofi while eitherfilm is in motion.

The exposed positive film is now-developed and fixed on both sides, after which the two sides are colored, each in a color different from the other, the two colors being selected to give a good rendering of the colors of the object photographed when the images on the two sides of the film are viewed simultaneously by transmitted light.

Usually the positive images made from the negative images which were taken through a green filter are colored red, and the. others, made from the negative images taken through a red filter, are colored green. The coloring may be effected by the well known Traube process or by the Miller method. In the preferred way of practising the Miller process the silver of the photographic image is bleached by conversion into a hydrosol of silver iodid by means of iodin in a solution of potassium iodid,after which the two sides of the film are treated with dyes (usually basic) of the proper colors. Upon washing the film the dyes are retained by the hydrosol but are Washed out of the gelatin elsewhere, thus leaving dye-images which are more or less transparent according to the extent to which the original silver of the image was converted into the hydrosol. This factor is easily regulated, as by varying the strength of the bleaching solution. I

By making both Geneva pin-wheels alike, as for example both like wheel 23, so that the two films will be fed equally instead of the negative faster than the positive, the printer can be used with negatives in which the two series of, images are on opposite sides of the film and in registry with each other, as in my co' ending applications Ser. Nos. 870,754, and 47,712. The shutters 12, 13 can then be omitted if desired and shutter 5 relied upon to prevent light striking the positive while the two films are in motion. The negative images on one side of thenegative are in one color, for example red, and in another color, for example green, on the other side. Behind the splitting prism light filters 18, 19, are provided, one green and the otherred, so that one side of the positive will receive only rays above, say, yellow of the spectrum, and the other only rays below green; or, if the filters are omitted, the

emulsions on the positive are sensitized (as 'by well understood methods) so as to be low affected only by rays of the proper color, as for instance on one side by rays above yeland on the other by rays below green.

With the filters in use the positive emulsions can be sensitized to the proper rays, as indicated, or both can be panchromatically sensitive. Of course the filters can also be used in printing from negatives of the kinemacolor type as already described, the positive emulsions being sensitive to the rays passed by the filters.

Another one-lens printer is illustrated diagrammatically in Fig. 8. Here the rays f 15111 the negative film 1 are projected by the lens and refiectedby mirrors 31, 38 to the emulsion 3 of the positive film 2 in film gate 37. Shutter 3 now obscures emulsion 3, after which the negative film is shifted one step (by feed mechanism like that illus trated in Fig. 5) and the rotating cam 33 on shaft 34, which has been holding the swinging mirror 31, pivoted at 32, against the stops 31 permits the spring 35 to swing the mirror out of the path of the'rays so that the latter reach the mirror 36. The exposure opening in shutter 4 then. reaches the film gate and exposes the emulsion 3. This exposure ended, both films are shifted one step, the cam 33 (suitably connected with the feed mechanism in any convenient, manner, not shown) swings the mirror back to its former position, and the shutter 3 exposes emulsion 3. This completes one cycle of operation. In the two-lens printer shown in Fig. 9 the films, 1, 2, are fed through the double film gate 39 by mechanism like that shown in Fig. 5, so that the negative film is shifted two steps to one of the positive. The negative is illuminated by lamps 40, 40 The rays from the negative are received by the mirrors 41, 44, and are projected by the lenses 42, to the mirrors 43, 46, whence they are reflected to the emulsions 3,4, on the positive film 2. The lenses, the axes of Which are parallel to the plane of the films, are adj ustablymounted in the wall of the housing, as by means of screw threads, for focusing purposes. For the same purpose the mirrors are mounted on sliding bases 48, 49, shifted by means of adjusting screws 48 49 The housing-wings 50 are mounted on the sliding bases and are connected to the main housing by the tongueand-groove construction shown to permit them to move with the bases without leakage of light into the housing. The desired registration of the images on the two sides of the positive film is roduced by tilting the mirrors 41, 44 on t eir vertical pivots 41 44*, and the mirrors 43, 46 on their horizontal pivots' 43 46 as willbe readily understood. For this purpose ,mirrors 43 and 46 are mounted as mirrors 9 and 10 (see Fig. 3

which illustrates the adjustable mounting), while mirrors 41 and 44 are mounted on vertical pins 41 in the base-plates 48, 49. Screws 41, on each side, enable the mirror to be tilted sidewise in either direction with ex- --shutter 51 opens and exposes emulsion 3.

This completes one cycle of operation. The lamps 40 may be extinguished while emulsion 4 of the positive film is being exposed, and lamps 40 extinguished while emulsion 3 is being exposedso thatonly rays transmitted through the negative are projected upon the positive.

The structure shown in Fig. 9 is described and claimed in my copending applications Ser. Nos. 870,754, filed Nov. 7, 1914, and

. 23,025, filed April 22, 1915, while the one- Ser. No. 815,153.

lens printer illustrated in Fig. 3 is similar to that described in my copending application Ordinarily the emulsions on the positive are sufiiciently opaque, considering the usually short duration of the exposures, to

prevent the passage of light through one emulsion in such amount as to affect the other. But if such interference should occur it can easily be prevented, as by sensitizing one side of the positive to one color, say red, and the other side to another color,

as green and then illuminating the negative with red light and green light in alternation, as by interposing red and green filters be tween the negative and the source of light, or alternate negative images (high lights ineluded) can be stained red and the others green.

It is ,to beunderstood that the invention is not limited to the devices herein specifically shown and described but can be embodied in other forms without departure '40 3.1 by-step film-feeding mechanism adapted to from its spirit.

I claim:

1. In a photographic printing apparatus for the purposedescribed, the combiv nation of positive andnegative film gates,

means for projectingimages from a film in.

the negative film gate upon opposite sides ofa film in-the positive film gate, and step- '1 advance the negative film two image-spaces each cycle. of operation.

2. In a photographic printing apparatus for the purpose described,- the combination 'jhnd the positive film one image-space mof positive and negative film gates, means for the purpose described, the combination of positive and negative'film gates, means for projecting images from a film in the negative film gate upon opposite sides of a film in the positivefilm gate, shutters arranged to "expose the opposite sides of the positive film alternately, and step-by-step film-feeding devices operating while both sides of the positive film are obscured and Or shutters like 51 and 52 can be provided between'the negative film and the lamps, for the same purpose.

adapted to advance the negative film two image spaces to one image-space of the positive 4:- In a photographic printing apparatus for the purpose described, the. combination of positive and negative film gates, means for projectingimages from a film in the negative film gate upon opposite sides of a film in the positive film gate, means for feeding a film step by step through the negative film 'gate, means for feeding a film in the positive film gate one step at connected with said means and with the.

positive film feed fsprocket to actuate the latter at each alternate actuation of the other sprocket.

6. In a photographic printing apparatus for the purpose described, the combination of positive and negative film gates, means for projecting alternately upon opposite sides of a film in the positive film gate images from a filmin the negative film gate, and Geneva-movement film-feeding mechanism adapted to advance the film in the negative film gate step by step and the film in the positive film gate one step at each alternate step of the other film.

7. In a photographic printing apparatus for the purpose described, the combination of a negative film gate, a projection lens to receive light from a film in said film gate, a light-splitting device to receive and divide the light from the lens, a positive film gate behind the light-splitting device, mirrors to receive light from the splitting device and reflect the same to the opposite sides of a film in the positive film ate, and means for feeding the films step lay. step through the film gates.

8. In a photographic printing apparatus for the purpose described, the combination of a negative film gate, a lens to receive light from a film in said film gate, a lightsplitting device behind the lens to divide the light therefrom, means for rotatably adjusting the splitting device about an axis thereof, a positive filmgate behind the splitting device, reflectors rotatably' adjustable on axes in a plane at right angles to the said axis of the splitting device to reflect the light from the splitting device to a film in the positive film gate, and.

means for feeding the films step by step jection lens between the film gates to receive through the film gates. I light from a film in the negative film gate,

9. In a photographic printing apparatus means for reflecting light from the, lens to r the purpose described, the combination the opposite sides of a film in the positive of a negative film gate; a projection lens film gate, mechanism for feeding the films 65 to receive light from a film in said film step by step through the fihn-gates, shutters gate; a light-splitting device behind the working on opposite sides of the positive lens to receive and divide the light received film gate to expose and obscure the film therefrom and provided with a surface artherein, and means for actuating the shut- 10 ranged at an angle to the axis of the lens, ters, connected with the said feeding mecha- 70 said surface having light-reflecting and nism for operation in harmony therewith light transmitting areas; a positive film to expose the film in the positive film gate gate behind the splitting device, mirrors only when the films are at rest. behind the splitting device to receive light 14. In a photographic printing apparatus therefrom and reflect the same to opposite for the purpose described, the combination 75 sides of a film in the positive film gate; of positiv and negative film gates, optical and means for feeding the films step by means to project successive images from a step through the film gates. film in the negative filfn gate upon opposite 10. In a photographic printing apparatus sides of a film in the positive film gate and for the purpose described, the combination in suitable registry with each other, and 80 of a negative film gate; a projection lens to mechanism for advancing the films step by receive light from a film in the said film step through the film gates.

j gate; a light-splitting device behind the 15. In a photographic printing apparatus lens; a rotatably adjustable mirror behind for the purpose described, the combination th splitting device to reflect light thereof positive and negative film gates; optical 85 from to one side of a film in the positive means, including a plurality of reflectors, film gate; reflecting means behind the splitfor projecting upon opposite sides of a film ting device to receive light therefrom and in the positive film gate and n suitable reflect the same to the other side of the film registry with each other successive images in the positive film gate; and means for upon a film in the negative film gate; step- 90 feeding the films step by step through the by-step film-feeding mechanism to advance film gates. I th films through the film gates and adapted 11. In a photographic printing apparatus to advance the film in the negative film gate for the purpose described, the combination at a faster rate than the film in the other;

of a negative film gate; a projection lens to means to illuminate the film in the negative 95 receive light from a film in the negative film film gate; and means to expose the film 1n gate; a ositive film gate behind the lens; the positive film gate only while both films devices f r reflecting light from thelens to are at rest.

the opposite sides of a film in the positive 16. In a photographic printing apparatus 40 film gate; means for feeding the films step for the purpose described, the combinat on 100 by step through the film gates; and means of positive and negative film gates; feeding for protecting from light both sides of the devices to advance films through the film in the positive film gate when the film gates; mechanism for actuating the feeding therein is in motion. devices to advance a film 111 the negative film 12. In a photographic printing apparatus gate two image-spaces to oneimage-space of 105 for the purpose described, the combination the film in the other gate; optical means of positive and negative film gates, a Erojecto pro ect upon opposite sides of the film in tion lens to receivev printing light om a, the positive film gate, and in suitable regisfilm in the negative film gate,mea-ns for re try with each other, successive images from 4 fleeting light from the lens to the opposite a in the negative film gate; means to 110 sides .of a film inthe positive film gate, illuminate the film in the negat ve film gate; mechanism for feeding the films step by step and shutter-mechanism operating in harthrough the film gates, and means connected mony with the aforesaid actuating mechawith the feedin mechanism to operate in mm to permit printing light from the film harmony therewith for exposing the film in in the, negative film ate to strike the other 115' fi t t' l' ht onl film onl while the ms are at rest. liei ii li fi lmgr e ag i slii mg 1g y In teszsimony whereof I have hereunto 13. In a photograph? griiilting alipargtus afiixed my signature. for the ur 'ose descri e t e com ma ion 0f positi e a ,nd negative film gates, a pro- PERCY DOUGLAS BREWSTER. 

